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Asymmetric Synthesis of O ‐Acetylcyanohydrins by Reaction of Aldehydeswith NaCN/KCN Catalyzed by Recyclable Chiral DimericTitanium(IV)/Vanadium(V) Salen Complexes
Author(s) -
Khan Noorul H.,
Agrawal Santosh,
Kureshy Rukhsana I.,
R. Abdi Sayed H.,
Mayani Vishal J.,
Jasra Raksh V.
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200600208
Subject(s) - chemistry , catalysis , acetic anhydride , vanadium , cyanide , sodium cyanide , potassium cyanide , enantioselective synthesis , potassium , medicinal chemistry , metal salen complexes , organic chemistry , polymer chemistry
The efficient catalytic asymmetric addition of an inexpensive and nonvolatile cyanide source such as NaCN or KCN and acetic anhydride to various aldehydes was catalyzed by recyclable dimeric Ti IV and V V chiral salen complexes at –20 °C. High chiral induction (96 % ee ) in the O ‐acetylcyanohydrin was obtained in the case of 2‐fluorobenzaldehyde, and the results achieved with sodium cyanide are quite comparable to those with potassium cyanide. The chiral V V salen complex was found to be the most efficient recyclable catalyst reported so far in the literature, and was better than the Ti IV salen system. Both the catalysts were recovered after the first use and recycled effectively four times. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)